Mechanical pencil



Jam 1942- F. c. DEL! ETAL MECHANICAL PENCIL Filed July 24, 1940 3 Sheets-Sheet l ATTORNEYS.

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Jan. 27, 1942. F. c. DELI EIAL MECHANICAL PENCIL Filed July '24, 1940 3 Sheets-Sheet 2 ZZZ BY b$.wood6 V0750; ATTORNEYS.

Jan. 27, 1942. F. c. DELI ETAL MECHANICAL PENCIL Filed July 24, 1940 3 Sheets-Sheet 3 b2 ATTORNEYS.

Patented Jan. 27, 1942 PATENT OFFICE,

MECHANICAL PENCIL' Frank C. Deli and Erik Pctau, Chicago,and Fred D. Woods, Glencoe, Ill., assignors to Autopoint Company, Chicago, Ill., a corporation of Illinois Application July 24, 1940, Serial No. 347,318

19 Claims.

This invention relates to mechanical pencils and more particularly to a mechanical pencil in which a long lead may be used, and one having improved features of construction including means to enable the quick straight longitudinal removal from the barrel of the actuating means at all times without the necessity of undergoing a tedious number of rotations of the actuating means with relation to the barrel.

In mechanical pencils of the type having either a spiral trackway member fixed in the barrel and a longitudinally slotted tube removable from the barrel or a slotted. tube fixed against movement in the barrel and a spiral-trackway member removable from the barrel and particularly so when along lead is used, it is tedious and time consuming to have to back up the plunger for receiving a new lead entirely by rotational movement even though the plunger may not have entirely reached its forward limit of travel.

Among the objects of the present invention are to make provisions for accomplishing the above advantages and to eliminate the disadvantages referred to in the foregoing.

Another object is to provide novel means for enabling the quick straight longitudinal pull of the actuating means of a mechanical pencil from the barrel, regardless of whether the plunger had reached its full forward limit of travel or not, whereby to inspect the actuating means or add a new lead as desired.

Another object is to make provision for novel connection of the outwardly available rotating means with the inner rotating part of the actuating means.

A still further object is to provide specially constructed means in the slotted tube for enabling the plunger head to recede inwardly from the spiral trackway to clear the same when that portion of the slotted tube is moved to the plunger head and vice versa.

Another object is to provide a novel plunger that may be used to propel either a full size lead or a thin lead as desired.

Still another object is to provide a special construction between the plunger head, the spiral trackway and the slotted tube.

A further object is to provide novel means for connecting a removable tip with the spiral trackway member mounted for rotation in and with relation to the barrel, and for detaching said tip and trackway member as a unit from the barrel.

A still further object is to provide novel means for permitting rotation of the spiral trackway in the barrel, and yet provide enough friction to prevent the same from unduly falling out of the barrel. I

Other objects, advantages and capabilities inherently possessed by our invention will later more fully appear.

Our invention further resides in the combination, construction and arrangement of parts illustrated in the accompanying drawings, and while we have shown therein preferredembodiments we wish it understood that the same are susceptible of modification and change without departing from the spirit of our invention.

In the drawings:

Fig. 1 is an enlarged longitudinal sectional view, partly broken away, of a mechanical pencil embodying our invention.

Fig. 2 is a view similar to Fi 1 but showing modified form of our pencil.

Fig. 3 is an enlarged side elevation, partly broken away, of the longitudinally slotted tube looking toward the slotted side.

Fig. 4 is a transverse section taken on the line 44 of Fig. 3.

Fig. 5 is an enlargedfragmentary side elevation of one end of the slotted tube taken at an angle of ninety degrees from the position shown in Fig. 3.

Fig. 6 is a transverse section taken on the line 8-4 of Fig. 5.

Fig. 7 is an enlarged fragmentary development of that portion of the slotted tube shown in Fig. 5, laid out flat prior to being rolled into cylindrical form.

Fig. 8 is a view similar to Fig. 7 but showing two slits in the lower end instead of one.

Fig. 9 is a transverse section taken on the line 9--9 of Fig. 1.

Fig. 10 is a transverse section taken on the line |0HI of Fig. 2.

Fig. 11 is an enlarged fragmentary longitudinal section of the lower end of a pencilshowing a further modified form.

Fig. 12 is an enlarged fragmentary longitudinal section of a still further modified form in which the tip is not removable from the barrel.

Fig. 13 is a view similar to Fig. 11 but showing another modification.

Fig. 14 is a development of the friction tube shown in Fig. 11, laid out fiat prior to being rolled into cylindrical form.

Fig. 15 is an enlarged fragmentary longitudinal section of the lower end of a pencil showing a still further modification.

Fig. 16 is an enlarged longitudinal section, with parts broken away, of a further modificationin which the tube with a spiral trackway remains fixed in the barrel and the slotted tube is removed from the barrel together with the cap ferrule by a-straight rearward longitudinal pull.

Fig. 17 is an enlarged fragmentary side elevation of the form of slotted tube shown in Fig. 16.

Fig. 18 is a transverse section taken on the line I ll-I8 of Fig. 17.

Fig. 19 is a transverse section taken on the line l9 9 of Fig. 16.

Fig. 20 is an enlarged longitudinal section through one form of connector for connecting the slotted tube to the removable cap ferrul in the form of pencil shown in Fig. 16.

Fig. 21 is a view similar to Fig. 20 but showing a modified form of connector.

Fig. 22 is an enlarged side elevation of a still further modified form of connector.

Fig. 23 is an enlarged fragmentary longitudinal section of the upper end portion of a pencil showing another modified form of connector.

Fig. 24 is an enlarged side elevation of a plunger for propelling the lead.

Fig. 25 is a view similar to Fig. 24 but showing the plunger after being rotated through an angle of ninety degrees.

Fig. 26 is a view similar to Fig. 25 but showing a modified form of plunger.

Fig. 27 is an end view of the plunger shown in Fig. 25.

Fig. 28 is an end view of the plunger shown in Fig. 26.

Our improved pencil is particularly adapted to and constructed for the use of long leads, thus giving longer use of the pencil for each lead and increasing the length of time before it is necessary to insert a fresh lead.

Referring more in detail to the drawings and first to Fig. 1, our improved pencil comprises a barrel I having a removable tip 2 within which and to rotate therewith is fixed the tube 3 provided with the spiral trackway 4, which in this form is a spiral slot. Surrounding the lower .end of spiral tube 3 is a sleeve 5 which serves as means to fix the spiral tube to the tip as Well as to provide friction means for holding the spiral tube rotatably in the barrel and yet permit its removal longitudinally with the tip. Sleeve 5 has molded therearound the body portion 6 of the tip formed of composition material which integrally enters the depression 1 in the lower end portion of the sleeve. The spiral tube 3 fits with a tight fit within the sleeve 5, these parts being further fixed together by the entry of projection 8 into the spiral slot 4. If desired, sleeve 5 may have a longitudinal slit or other form of slit in its upper end portion to form friction spring means to facilitate a rotational friction fit with the bore 9 in the barrel. Sleeve 5 also strengthens the joint between the tip and barrel but is not indispensable for the proper functioning of themechanism, and may be omitted if desired by making the bore of the barrel small enough to rotatably receive the spiral tube and firmly secure the spiral tube directly to the tip.

Within the spiral tube is a longitudinally slotted tube l formed with the bore H and slot l2, and fixed at its upper end l3 by a tight press fit within the metal eyelet l4 formed with the head [5. The eyelet I4 is preferably held by a tight press fit within the upper end of the bore in the barrel, and is further held against movement with relation to the barrel by having the circumferential outer edge of head I tightly held between the spaced projections l6 and H formed in the metal eraser head sleeve l8, which in turn is tightly held with a press fit over the reduced upper end of the barrel to prevent its being pulled off from the barrel. The eyelet I4 and the eraser head 18 may be fixed together by soldering or staking if desired. The upper end of sleeve I8 is formed to receive the.holder l9 of eraser 20. Removably positioned over sleeve I8 is the cap 2| for covering the eraser.

Sleeve 5 is reduced in diameter at its lower end at 22 to be rotatable with relation to the slotted tube l0. Also fixed to the lower end of the tip body 6 is the conical metal end 23, the lower end of which is flanged at 24 to rotatably receive the flange 25 of the closing bushing 26, which is of such internal diameter as to press towards each other the normally outwardly springing halves 21 and 28 of the projecting lower end of the slotted tube In to cause them to grip the lead with sufficient force to prevent the lead from falling out of the tip and yet permit the lead to be forced out of the end of the tip as it is pushed by the propeller 40 during relative rotation of the tip and barrel. In this form of pencil the slotted tube l0 projects beyond the lower end of th tip and itself forms the end portion through which the lead is extruded.

The slotted tube It is formed by rolling into cylindrical form a flat blank of the proper form, the fragmentary lower end of such flat bank being shown in Fig. '7 which is formed with a slit 29 which together with the sides 30 and 3| form two diametrically opposite slits when the blank is rolled into cylindrical form to form the two halves 21 and 28, which are caused to normally tend to spring outwardly when the tip is removed to permit a fresh lead to be easily pushed into the slotted tube for reloading purposes. In the form of blank shown in Fig. 8 there are provided two slits 32, 33 which together with the two sides 34, 35 form three circumferentlally spaced slits when the blank is rolled into cylindrical form for the same pu pose as the slits referred to above in connection with Figs. 7 and 5.

In the blanks shown in Figs. 7 and 8 are formed trrth'e side edges just above the edges 30, 3|, 34 and 35 the cutaway portions having the inwardly and downwardly inclined sides 36 and the short straight portion 31 so arranged that when the blank is rolled into cylindrical form there will be formed in the slotted side of the slotted tube In an inclined depression or recess 38 shown in Figs. 3 and 5. The purpose of the inclined recess 38 is to receive the head 39 of the plunger 40 to permit it to move thereinto and thus free Head 39 from the spiral slot 4 of spiral tube 3 by moving inwardly therefrom when head 39 and recess 38 come opposite each other during the travel of the head in the spiral slot. The plunger 40 back of the head 39 is of such size and shape that when the plunger head comes opposite the recess 38 the head 39 will move radially inwardly to move the head out of contact with the spiral slot. This inward movement will be induced by the camming action between the head and spiral slot 4, and by the inclined portion t of the plunger contacting the closed forward end u of the slot and being forced inwardly thereby.

It will thus be seen that upon rotation of the tip and spiral tube in proper direction with relation to the barrel to cause the plunger head 39 to move toward the tip during the forward feeding .of the lead, the head 39 will enter recess 38 when the lead is exhausted. This frees the head from engagement with the spiral slot and the tip and attached spiral tube 3 may be pulled by a straight longitudinal pull out of and away from the barrel with the slotted tube and plunger 40 remaining in the barrel. A new lead may then be pushed into the forward end of the slotted tube ill, the jaws or halves 21 and 28 of which will now be sprung apart. Upon pushing said new lead against the end of the plunger, the latter will be pushed rearwardly by alongitudinal sliding action 50 that the plunger head occupies a'position at or near the rear end of the slot II and has been moved by the inclined edges 36 diametrically outward to a position to again enter and follow the spiral slot 4 when the spiral tube 3 has been pushed into the barrel and rotated in the proper direction sufficiently to pick up the plunger head within the spiral slot of the spiral tube. The pencil is then ready for use with a new lead.

It is thus seen that when the lead is exhausted the spiral tube may be quickly pulled out of the barrel by a straight longitudinal pull without having to laboriously rotate the tip and barrel with relation to each other a considerable number of times, and a new lead inserted and the spiral tube reinserted into the barrel by a straight longitudinal push without the necessity of a large number of rotational movements. The forward or lower end of the slotted tube Ill will preferably be bevelled as shown at 4| to give a more pleasing appearance as this part is exposed beyond the lower end of the tip.

At suitably circumferentially spaced distances around the interior of the barrel are any desired number of longitudinally extending openings 42 to receive and store extra leads available from the tip end upon removal of the tip and spiral tube. In Fig. 10 four of these extra lead pockets are shown and five in Fig. 9. These extra lead openings 42 do not extend throughout the length of the barrel but are closed at the upper end so as to provide a secure hold for the metal and anchor them to that end of the barrel.

In Fig. 2 is shown a modified form of pencil generally similar in construction and operation to the pencil of Fig. 1 except for differences that The upper end 13 of the slotted tube I0 is -fixed will now be pointed out. In Fig. 2 the spiral tube 3 is provided with a spiral groove 4' formed between the spiral ridges 43 spun or rolled into the tube or otherwise formed as desired. The tube 3' is fixed to the tip 6 by a press fit or by having the plastic composition body of the tip molded in place around the lower end portion of the tube if desired. The lower end of the slotted tube 10, as in Fig. 1 extends beyond the tip member, and is provided with the jaws 21, 28 and for the same purpose, these jaws being forced toward each other by the tubular lower end 44 of tube 3 when the latter is inserted into the barrel which in turn applies the tip member in place thereon. The jaws (which may be any suitable number desired) when the tip is applied to the barrel thus apply sufficient friction to the lead to prevent it from falling out and yet permit it to be pushed forwardly by the plunger. The plunger head rides in the groove 4 except when it comes opposite the recess 38, at which time the head moves radially inwardly away from the spiral groove the same as it moved inwardly away from the spiral slot 4 in Fig. 1 and for the same purpose.

Also the spiral tube 3' in Fig. 2 is formed for a portion of its length with a slot 45, the metal on each side thereof being bulged outwardly a suiiiclent amount to create enough friction between the tube and the barrel to prevent the tube from falling out of the barrel and yet permit it to be rotatable therein. Fixedly held by a press fit or in any other desired manner in the upper end of the bore of the barrel, is a connector 46 provided with the flange 41 seated in a recess in the upper end face of the barrel.

by a press fit or otherwise as desired, inside of the connector 46 so that the slotted tube will be fixed to the barrel at all times. The metal flange 41 of the connector 46' is spaced away from the metal ferrule 18, hence'no metallic contact is possible between the tip and the eraser end of the pencil. Fixed over a reduced portion of the upper end of the barrel is a ferrule 18' the upper open end of which receives the holder l9 of the eraser 20, and which ferrule may receive and hold a clip if desired. It will thus be seen that rotation of the tip with relation to the barrel will, depending upon the direction of rotation, cause the plunger head 39 to move longitudinally along the slot l2, being driven therealong by the spiral groove 4'. When the plunger head upon exhaustion of the lead comes opposite the'recess 38 itwill move radially inwardly and out of operating relationship to the spiral groove 4', whereupon the tip member and spiral tube 3' may be pulled by a straight longitudinal pull away from and out of the barrel as described in connection with Fig. 1. Also a new lead may be inserted and the parts reassembled as in Fig. 1.

The modifications shown in Figs. 11 and 13 also operate generally in the same manner as the pencils of Figs. 1 and 2. The differences in Figs. 11 and 13 will now be described. As will be noted, Fig. 11 shows a pencil in which the spiral tube 3 is formed with a spiral slot 4, while the spiral tube 3 of Fig. 13 is formed with spiral grooves defined-by the =.internally extend- :iEnig szpiral ridges 50 similar to the ridges 43 in In Fig. 11 the longitudinally slotted tube I0 is, like Fig. 1, formed with the inclined recess 38 into which the plunger head 39 enters to free the head from the spiral slot 4 as in Fig. 1, and for the same purpose. Also the tip is formed of a composition body 53 and a concentric metal nose 54 of conical shape and continuing smooth and uninterrupted taper. The upper'end 55 of nose 54 is of reduced diameter and continues upwardly part way into the bore of the tip body 53 and is fixed thereto either by molding or otherwise as desired. Also molded or otherwise fixed within the bore of the tip body 53 and continuing in alignment with the tubular end 55 ,of nose 54 to extend a way into the barrel is a slotted sleeve 56 which is rolled into cylindrical form from the fiat blank 51 shown in Fig. 14, and provided with a plurality of slots 58. These slots give resiliency in a radial direction to tube 55 and enable it to be pushed into the lower end of the bore of the barrel to provide a friction fit to rotatably hold the tip to the barrel and enable it to be removed therefrom by a longitudinal pull when desired. The spiral tube 3 is also held within sleeve 56 sufliciently tightly to cause the spiral tube to rotate within 'the barrel with the tip and be pulled therewith out of the barrel by a straight longitudinal pull as described in connection with Fig. 1. In each of Figs. 11 and 13 the longitudinally slotted tube Ill (not shown in Fig. 13) are each fixed at its upper end to the barrel as in Figs, 1 and 2, while the spiral tube is fixed to the tip t rotate therewith and with relation to the barrel;

The tip construction in Fig. 13 is similar to that in Fig. 11 except that the slotted sleeve 55 is omitted and the lower end of the spiral tube 3 is fixed in the composition tip body 53 and also,'if desired, in the reduced end 55 of the metal nose 54. The spiral tube 3 in Fig. 13, for a portion of its length within the barrel is, like Fig. 2, provided with a slot 45 with slightly expanded edges and for a similar purpose.

In this form, like those previously described, the tip member 5355 and the spiral tube 3 are together as a unit removable from the barrel by a straight longitudinal pull and are together rotatable with relation to the barrel, the slotted tube carrying the plunger being fixed with relation to the barrel.

In the form shown fragmentarily in Fig. 15, the tip member and the spiral tube are likewise removable as a unit from the barrel by a straight longitudinal pull, and are as a unit rotatable with relation to the barrel. In this form the tip member consists of the composition body member 59 molded or otherwise fixed to the sleeve 69 and has fixed at its lower end the metal conical member 6| which may have the composition body member molded thereto or otherwise fixed as desired. The opening in the lower end of the conical member BI is of a size to cause the outwardly expandible members or jaws 21 and 28 of the slotted tube to be squeezed or forced together when the tip member is applied to the 5 barrel sufficiently to grip the lead to prevent the same from falling out of the slotted tube but permit the lead to be moved therethrough by the plunger during the feeding operation of the pencil. The slotted tube I0 is of the same construction as that in Fig. 1, it being fixed at its upper end to the barrel after the manner shown in Figs. 1 and 2, or in any other suitable manner desired.

In Fig. the spiral tube 3 is formed with an open spiral slot 4, but it willbe understood that if desired this spiral trackway may be in the form of a spiral groove such as shown in Fig. 2. The sleeve 60 is shown in Fig. 15 as being insertible into a counterbore 62 in the barrel and may, if desired, be formed with a straight or curved slot to provide friction means to prevent the tip and spiral tube from falling away from the barrel and at the same time afford sufiicient friction to enable easy rotation of the tip and spiral tube with relation to the barrel. The spiral tube 3 is fixed to sleeve 60 by means of the inwardly extending projection 63 which extends into the spiral slot 4, or spiral tube 3 may be fixed to rotate with sleeve 80 and the tip member in any other suitable manner desired. It will thus be seen that the tip member, the sleeve 60 and the spiral tube 3 are thus fixed together to function as a unit. The lower end of the spiral tube 3 abuts against the shoulder 64 of the lower end of sleeve 50, the latter extending in reduced diameter downwardly substantially into contact with the inner face of the metal conical member 6|. As shown in the views previously described, the slotted tube In of Fig. 15 is provided with a recess 38 to receive the plunger head 39 and permit disengagement of said plunger head from the spiral slot 4 when said plunger head and recess 38 come into registry. The pencil of Fig. 15 is also provided with reserve lead longitudinal openings 42 as described in connection with the preceding figures.

In Fig. 16 is shown a'modifiedform of pencil in which the slotted tube 65 is rotatable with relation to the barrel 66 and removable therefrom by a straight rearward longitudinal pull. In this form the tip member 61 is fixed with relation to the barrel and may be integral therewith or fixed thereto as desired. In this form the spiral tube 68 is also fixed with relation to the barrel and to the tip. The tip 81 may be molded in the lower end of the barrel with the composition material of the barrel filling the depression 69, or otherwise fixed as desired. The depression 69 is formed by inwardly pressing the metal of the upstanding neck 19 to form a projection H which extends into the lower end of the spiral slot 1 I, and

which spiral slot where the spira1 tube enters the lower end of the barrel may be molded into position therein or otherwise fixed as desired. This rigidly fixes the spiral tube 68 to the tip of the pencil and holds said spiral tube against rotation with relation to the barrel. The lower end of the slotted tube 65 may be formed with diametrically opposite slits 12 which normally tend to spring apart a slight distance so that when the slotted tube is inserted the full distance into the spira1 tube, two jaws 13 and 14 will contact the inner face of the metal nose 6! of the tip and force them together a sufficient amount to grip the lead and prevent it from falling out of the pencil, and at the same time enable it to be pushed longitudinally by the plunger during the feeding operation. Also, if desired, the extreme end of the tip may be provided with slits to hold the lead.

In Fig. 16 the plunger head 39 is shown near the bottom end of the barrel with the plunger 48 just emerging below the bottom end of the slotted tube 65 with the lead not yet quite exhausted. The upper end 18 of the spiral tube 68 is shown slightly spaced from the connector 19, which connector as shown in Fig. 16 comprises the head having the integral downwardly extending sleeve 8|, within which sleeve is fixed by a press fit or otherwise as desired the upper end of the slotted tube 65, which slotted tube will also extend upwardly through the head 80 with a press fit, the extreme upper end of the slotted tube being swedged outwardly into a complemental recess as indicated in Figs. 16 and 22. The head 80 of the connector is fixed by suitable inwardly extending projections 82 to the ferrule 83, which ferrule is mounted upon a reduced end 84 at the upper end of the barrel for rotation thereon. Mounted in the upper open end of ferrule 83 is the holder l9 of eraser 20. If desired, a cap may be removably placed over the eraser 20 and ferrule 83.

Adjacent the lower end thereof the slotted tube 65 is cut away at both sides of the longitudinal slot 85 to form the inwardly inclined surface 88, which at its lower end merges into the straight portion 81 to form the recess 88 corresponding to recess 38 in Figs. 1, 2, 3. 5, 11 and 15 to receive the plunger head 39 and free the same from the spiral slot II when the plunger head comes opposite recess 88, and for a similar purpose to that described in connection with the preceding figures of the drawings.

It will thus be seen that in the form of pencil shown in Fig. 16, the spiral tube 68 and the tip are fixed with relation to the barrel 66, while the slotted tube 55, the connector 19, 80 and 8|, and the ferrule 83 are rotatable as a unit with relation to the barrel and removable as a unit therefrom by a straight rearward longitudinal pull. When the lead has become exhausted by a rotational movement of the slotted tube with relation to the barrel, or at any position of the plunger previous thereto, a straight rearward longitudinal pull upon the ferrule 83 will carry with it a corresponding movement of the connector and slotted tube and bring the recess 88 into registry with the plunger head 39 (unless it is already there due to the exhaustion of the lead) and the plunger head will move inwardly into the recess and become disengaged from the spiral slot ll of the spiral tube 68 as described earlier herein. This at once frees the plunger head from the spiral tube and permits rearward removal of the slotted tube from the barrel for introduction of a new lead or for inspection if desired. Upon introduction of a new lead the plunger head and plunger will by contact with the lead be pushed rearwardly, so that the plunger head will ride upon the metal of the slotted tube at the sides of the slot 85 above the recess 88 and, when the slotted tube is pushed into the barrel, rotation of the ferrule 83 and slotted tube will bring the plunger head again into the rear open end of the spiral slot of the spiral tube, and the parts will then be in position for forward feeding of the lead upon rotation of the ferrule with relation to the barrel. The form of pencil shown in Fig. 16 is, like those previously described, provided with longitudinally extending openings 42 to form reserve lead magazines of which any suitable and desirable number may be provided in the barrel and, as shown in this form of pencil, the open end of such lead magazines is made available at the upper end of the pencil by removal of the ferrule 83 and its associated parts.

The connector shown in Fig. 22 is substantially the same as that shown in Fig. 16. The connector shown in Fig. 20 is of somewhat different form than that shown in Fig. 16 and, as seen, is constructed of the hollow metallic member 89 with an upwardly extending integral inner sleeve 80 with a cylindrical bore to receive the upper end of the slotted tube 65 with a press fit, the outer walls of this connector being also connected by a press fit or any other suitable connecting means to the ferrule 83. The connector shown in Fig. 2I is similar in exterior appearance to that shown in Fig. 22 except the former is hollow as shown to receive within the inner bore 92 the upper end of the slotted tube 65 with a press fit, and the exterior of the upper portion 93 is secured by a press fit or otherwise as. desired to the inside of ferrule 83 so that these parts will rotate together as a unit. In Fig. 23 the connector 94 is shown as a solid collar with a cylindrical central bore extending therethrough, through which bore 95 the upper end of the slotted tube 65 extends and is attached thereto with a press fit, while the exterior of connector 94 is secured to the ferrule 83 by means of indentations 82 similar to those shown in Fig. 16. In Fig. 23 the upper end of the slotted tube is swedged over into a suitable counter-bore as shown at 86. I

The plunger 40 as shown in Figs. 24 to 28 is formed with a neck 91 of such size and shape that when the plunger head 39 is at any part of the slot of the slotted tubeother than the recess 88 or 38 and inclined sides 86 or 36, the upper end of the plunger will be slidable in the slot, and when the head 39 arrives opposite the recess 88 or 38 the head will automatically move laterally inwardly away from the spiral trackway of the so that the head will move longitudinally, free of the spiral trackway, when pulled from the barrel spiral tube a sufficient distance to clear the same 76 either by the ferrule at the upper end, or the tip at the lower end, depending upon which form of pencil is being used.

The form of plunger shown. in Figs. 24, 25 and 27 is for the standard lead of .046 inch diameter, while the plunger shown in Figs. 26 and 28 shows a structure which is capable of use with either the standard lead just referred to or the thin lead of .036 inch diameter without any dimensional changes. The slot 91 extending upwardly a slight distance longitudinally preferably along the central lower portion of the plunger would permit the plunger to spread to approximately the full internal diameter of the slotted tube and accommodate the end area of either the standard lead or the thin lead, and also allow the plunger to enter the grip-tight orifice of the tip without doing any damage when it is necessary to eject the lead, thus enabling the use of one size of plunger for both standard and thin leads. It is thus seen that we have provided a plunger capable of use either with the standard size lead or with thin leads without any structural changes.

The modification shown in Fig. 12 is similar to the form of pencil shown in Fig. 16 in that the tip I00 and the spiral tube IOI are both fixed to the barrel and the slotted tube I02 is rotatable with relation to the barrel after the manner shown in Fig. 16 and described above in connection therewith. In Fig. 12 the spiral groove I03 in the spiral tube IN is formed by rolling, spinning or the like inwardly, the inner side of which groove forms a spiral ridge, and the space I04 between adjacent spiral ridges forms a spiral trackway within which the plunger head is moved during the operation of the pencil. The spiral tube IOI is extended into the upwardly extending sleeve I05 of the metal tip and may be soldered or otherwise fixed thereto as desired. Also, if desired, that portion of the spiral tube IOI extending into the tapered composition portion I06 of the tip cone may have the latter molded therearound or be otherwise fixed thereto as desired in order to be stationary with relation to the barrel. In this form when the plunger head 39 enters the recess 38 said head Will move radially inward away from the ridges of the spiral trackway I04 and thus be in position to permit the slotted tube and plunger to be freely pulled rearwardly and out of the spiral tube by a straight longitudinal pull to enable a new lead to be inserted therein. In Fig. 12 there are also provided longitudinally extending openings 42 which serve as storage spaces for extra leads.

Having now described our invention, we claim:

1. In a mechanical pencil, a barrel, a tip member rotatably connected with the barrel, a tube fixed to the tip member to rotate therewith and normally extended into the barrel, said tube having a spiral trackway, a slotted tube fixed to the barrel and normally extending into the first mentioned tube, a headed plunger slidably mounted in the slotted tube with the head of the plunger positioned on the outside of and overlapping the slot and normally in engagement with said spiral trackway for the greater part of its length, said slotted tube having a recess adjacent one end of the slot in alignment therewith, into which recess the plunger head moves radially inward to clear the spiral trackway, the tip member and first mentioned tube being removable as a unit from the barrel by a straight longitudinal pull,

the plunger remaining at all times in the slotted tube, the plunger head being pushed back to the rear end of the slot by the insertion of a new lead through the tip end of the slotted tube, and the first mentioned tube being reinsertible into the barrel by a straight longitudinal push until its rear end strikes the plunger head which is then movable into the spiral trackway by a rotational movement of the tip with relation to the barrel.

2. In a mechanical pencil, a barrel, a tip, a tube having a spiral trackway, a slotted tube having a longitudinal slot closed at its forward end, a plunger longitudinally movable in said slotted tube, a head fixed on the plunger and of a width to extend sidewise beyond both edges on the outer side of the slot in the slotted tube, a recess formed in the material of the sides of the slot adjacent the forward end of the slot and in alignment with the slot sides, the slotted tube and the first mentioned tube being rotatable and longitudinally movable with relation to each other, the plunger head entering said recess to be free from said trackway when the head and recess come opposite each other.

3. In a mechanical pencil, a barrel, a tip, a tube'having a spiral trackway, a slotted tube having a. longitudinal slot closed at its forward end, a plungerlongitudinally movable in said slotted tube, a head fixed on the plunger and of a width to extend sidewise beyond both edges on the outer side of the slot in the slotted tube, a recess formed in the material of the sides of the slot adjacent the forward end of the slot and in alignment with the slot sides, the slotted tube and the first mentioned tube being rotatable and longitudinally movable with relation to each other, the plunger head entering said recess to be free from said trackway when the head and recess come opposite each other, one of said tubes being removable from the barrel by a straight longitudinal pull when said head and recess meet.

4. In a mechanical pencil, a barrel, a tip, a tube having a spiral trackway, a slotted tube having a. longitudinal slot closed at its forward end, a plunger longitudinally movable in said slotted tube, a head on the plunger of a width to extend sidewise beyond both edges on the outer side of the slot in the slotted tube, a recess formed in the material of the sides of the slot adjacent the forward end of the slot and in alignment with the slot sides, the slotted tube and the first mentioned tube being rotatable and longitudinally movable with relation to.each other, the plunger head entering said recess to be free from said trackway when the head and recess come opposite each other, one of said tubes being removable from the barrel by a straight longitudinal pull when said head and recess meet, the material of the sides of the slot at the upper end of the recess being inclined to cause the plunger head to ride upwardly along said inclines to force the head radially outward into position for engagement with the spiral trackway when the plunger is pushed rearwardly of the slot by contact with a new lead.

5. In a mechanical pencil, a barrel having a longitudinal bore therein, a tip, a tube in said bore, a slotted tube in said spiral tube, a plunger having a head rigidly fixed thereon and projecting through said slot and overlapping the sides of the slot and movable therealong, a recess formed in the material of the sides of the slot and in longitudinal alignment therewith, the

first mentioned tube being formed with a spiral trackway to receive said head, one of said tubes being rotatable with relation to each other to longitudinally move the plunger and feeda lead, and one of said tubes being longitudinally movable with relation to the other and withdrawable from the barrel by a straight longitudinal pull when the plunger head comes opposite said recess. Y

6. In a mechanical pencil, a barrel having a longitudinal bore therein, a tip, a tube in said bore and having a spiral trackway, a slotted tube in said first mentioned tube, a plunger having a head rigidly fixed thereon and projecting through said slot and overlapping the sides of the slot and movable therealong to normally hold the head in engagement with the first mentioned tube, a recess formed in the material of the sides of the slot in longitudinal alignment therewith, the plunger head being movable into the recess and radially away from the first mentioned tube when the head and recess are radially opposite each other, one of said tubes being rotatable with relation to the barrel and the other being fixed with relation thereto.

7. In a mechanical pencil, a barrel having a longitudinal bore therein, a tip, a tube having a spiral trackway and fixed with relation to the tip, a slotted tube in the first mentioned tube, a plunger longitudinally movable in the slotted tube, a head fixed on said plunger and extending through said slot and overlapping the same and normally in engagement with said first mentioned tube, a recess in the material of the sides of the slot in alignment therewith, the head of the plunger moving radially inward into the recess when they come opposite thereto.

8. In a mechanical pencil, a barrel having a longitudinal bore therein, a tip, a tube having a spiral trackway and fixed with relation to the tip, a slotted tube in the first mentioned tube, a plunger longitudinally movable in the slot-ted tube, a head fixed on said plunger and extending through said slot and overlapping the same and normally in engagement with said first mentioned tube, a, recess in the material of the sides of the slot in alignment therewith, the head of the plunger moving radially inward into the recess when they come opposite thereto, one of said tubes being removable. from the barrel by a straight longitudinal pull.

9. In a mechanical pencil, a barrel having a. longitudinal bore therein, a, removable tip, a tube having a spiral tracking and fixed to the tip to rotate therewith, said tip and tube being rotatable together as a unit with relation to the barrel, a slotted tube fixed to the barrel and normally extended thereinto, a plunger in said slotted tube and having a head extending through and overlapping the slot of the slotted tube, and a recess formed in the material of the sides of said slot in longitudinal alignment with the slot.

10. In a mechanical pencil, a barrel having a longitudinal bore therein, a removable tip, a tube having a spiral trackway and fixed to the tip to rotate therewith, said tip and tube being rotatable together as a unit with relation to the barrel, a slotted tube fixed to the barrel and normally extended thereinto, a plunger in said slotted tube and having a head extending through and overlapping the slot of the slotted tube, a recess formed in the material of the sides of said slot in longitudinal alignment with the slot, and a connector element for fixing the slotted tube to the barrel.

11. In a mechanical pencil, a barrel having a longitudinal bore therein, a removable tip, a tube having a spiral trackway and fixed to the tip to rotate therewith, said tip and tube being rotatable together as a unit with relation to the barrel,

a slotted tube fixed to the barrel and normally extended thereinto, a plunger in said slotted tube and having a head extending through and overlapping the slot of the slotted tube, a recess formed in the material of the sides of said slot in longitudinal alignment with the slot, and a conhector element for fixing the slotted tube to the barrel, the tip and first mentioned tube being removable together as a unit from the barrel and from the slotted tube by a straight longitudinal pull when the plunger head comes opposite the recess.

12. In a mechanical pencil, a barrel having a longitudinal bore therein, a removable tip, a tube having a spiral tra-ckway and fixed to the tip to rotate therewith, said tip and tube being rotatable together as a unit with relation to the barrel, a slotted tube fixed to the barrel and normally extended thereinto, a plunger in said slotted tube and having a head extending through and overlapping the slot of the slotted tube, a recess formed in the material of the sides of said slot in longitudinal alignment with the slot, and a connector element for fixing the slotted tube to the barrel, the tip and first mentioned tube being tube having a spiral trackway and fixed to the tip to rotate therewith, said tip and tube being rotatable together as a unit with relation to the barrel, a slotted tube fixed to the barrel and normally extended thereinto, a plunger in said slotted tube and having a head extending through and overlapping the slot of the slotted tube, a recess formed in the material of the sides of said slot in longitudinal alignment with the slot, a connector element for fixing the slotted tube to the barrel, the tip and first mentioned tube being removable together as a unit from the barrel and from the slotted tube by a straight longitudinal pull when the plunger head comes opposite the recess, and friction means formed in connection with the first mentioned tube for frictionally holding the first mentioned tube in the barrel for rotational movement therein and longitudinal withdrawal therefrom.

14. In a mechanical pencil, a barrel having a longitudinal bore therein, a removabletip, a tube having a spiral trackway and fixed to the tip to rotate therewith, said tip and tube being rotatable together as a unit with relation to the barrel, a slotted tube fixed to the barrel and normally extended thereinto, a-plunger in said slotted tube 5 and having a head extending through and over-' lapping the slot of the slotted tube, and a recess formed in the material of the sides of said slot in longitudinal alignment with the slot, the tip and first mentioned tube being removable together as a unit from the barrel and from the slotted tube by a straight longitudinal pull when the plunger head comes opposite the recess, the forward end of the slotted tube beyond the recess being closed with relation to the slot and formed with a plurality of normally outwardly urged jaws, the tip forcing said jaws together to grip a lead sufficiently tight to prevent it from falling out and yet be moved forwardly by the plunger.

15. In a mechanical pencil, a barrel, a tip, a tube having a spiral trackway, a slotted tube, a plunger longitudinally movable in said slotted tube, a head in said plunger extending through the slot of said slotted tube and overlapping the slot sides, the ends of said slot being closed, and a recess formed in the material of the sides of said slot adjacent one end, said slotted tube being of cylindrical shape and having an inclined recess in its side edge.

16. In a mechanical pencil, a barrel, a tip, a tube having a spiral trackway and fixed to said tip to normally extend into a bore in the barrel, a slotted tube fixed to the barrel and having a longitudinal slot therein, said slotted tube having a recess in one end of the slot and in alignment therewith, a slotted sleeve fixed in saidtip and extending upwardly into the barrel, the slots of said sleeve affording resiliency to cause the sleeve to have a frictional slip fit in the barrel to en- 5 able rotation of the tip and first mentioned tube as a unit with relation to the barrel and removal of the same from the barrel by a straight 1ongitudinal pull when the plunger head is in the recess.

1'7. In a mechanical pencil, a barrel, a tip, a tube fixed within the barrel and having a spiral trackway, a slotted tube rotatably positioned within the first mentioned tube, a plunger longitudinally movable in the slotted tube, said plunger having a head extended outwardly through the slot of the slotted tube and overlapping the outer sides of the slot to hold the head in engagement with the first mentioned tube throughout the greater extent of the length of the slot, said slotted tube having a recess formed in a side wall of said slot in communication therewith, movement of the parts such as to bring the plunger head and recess into registry with each other enabling removal of the slotted tube from the barrel and first mentioned tube by a straight longitudinal pull for introduction of a new lead, and rotation of the slotted tube within the first mentioned tube causing lead-feeding movement of the plunger when the plunger head 0 and recess are out of registry.

18. In a mechanical pencil,a barrel, a tip, a tube fixed within the barrel and having a spiral trackway, a slotted tube rotatably positioned within the first mentioned tube, a plunger longitudinally movable in the slotted tube, said plunger having 'a head extended outwardly through the slot of the slotted tube and overlapping the outer sides of the slot to hold the head in engagement with the first mentioned tube to throughout the greater extent of the length of the slot, said slotted tube having a recess formed in a side wall of said slot in communication therewith, movement of the parts such as to bring the plunger head and recess into registry with each other enabling removal of the slotted tube from the barrel and first mentioned tube by a straight longitudinal pull for introduction of a new lead, and rotation of the slotted tube within 7 the first mentioned tube causing lead-feeding movement of the plunger when the plunger head and recess are out of registry, a ferrule rotatably and removably mounted on the upper end of the barrel, and a connector fixed to the slotted tube and ferrule to cause rotation of th slotted tube with relation to the barrel by the operator grasping and rotating the ferrule, and removal of the slotted tube from the barrel by a straight rearward pull upon the ferrule.

19. A plunger for mechanical pencils of the type having radially movable jaws at the forward end of the tip for slidably gripping leads of different diameters, characterized by an elongated body portion, and a head, the body portion having a. longitudinally extending slot, the slotted end of the body portion being normally expanded sufficiently to operatively contact the end 01. either a large lead or a thin lead, and be compressed radially sufliciently to pass through the tip for either a large lead or a thin lead.

' FRANK C. DELI.

ERIK PETAU. FRED D. WOODS. 

